Editorial
Backpacks in children
Sri Lanka Journal of Child Health, 2011; 40: 1-3
(Key words: Backpacks; children)
All parents want their children to do well in school.
They make sure that children bring home their books
and do their homework at night. They also ensure
that they have their books packed away in their
backpacks ready to be taken to classes the next day.
However, they may be overlooking a threat to their
children's health. Recently scientists have begun to
examine the effects of carrying heavy backpacks full
of books. What they have discovered is that carrying
heavy backpacks may pose a serious threat to the
child's spinal development.
Of the factors linked with back pain in
schoolchildren, none has stimulated greater parental
anxiety than the use of school backpacks. Viry et al1
studied the effects of school backpack weight on the
presence of nonspecific low back pain in 123 eighthgraders in France. The authors concluded that
nonspecific adolescent back pain was associated with
female gender and carrying a backpack weighing
more than 20% of the student’s body weight3.
Grimmer and Williams2 surveyed 1,269 high-school
students in Adelaide, South Australia, and recorded
backpack load as a percentage of total body weight
and height. The authors found a strong association in
all grades between low back pain and both backpack
weight and the length of time carried2. Again, girls
were more likely to report low back pain than boys;
girls’ description of back pain increased in year 8,
while boys reported a similar response 1 to 2 years
later. The authors suggested that this finding may
represent the relationship between the different peak
growth phases between genders and the susceptibility
of rapidly growing spines to back pain2. More than
one fifth of the students were found to carry
backpack loads greater than 10% of their body
weight2.
Siambanes et al3 studied 3,498 students living in two
counties in California where each student’s weight
and backpack load were measured. Controlling for
age, socioeconomic status, walking to and from
school, and method of wear, results indicated that
backpack weight, measured as a percentage of body
weight, was effective in predicting back pain (P <
0.01). Girls and those who walk to and from school
were more likely to report back pain (P < 0.01)3.
Negrini and Carabalona4 recently performed a crosssectional study of 237 sixth-graders in Milan, Italy.
The children reported that their backpacks were
heavy (79%), caused fatigue (65.7%), and caused
back pain (46.1%). No significant difference between
genders was detected4.
The weight of schoolbags and the prevalence of
musculoskeletal symptoms amongst 140 students (70
third form students comprising 35 females and 35
males, and 70 sixth form students comprising 35
females and 35 males) from five New Zealand
secondary schools was investigated5. Schoolbag
weight for third form students (mean age 13.6 years)
was 13.2% of their body weight, while for sixth form
students (mean age 17.1 years) it was 10.3% of their
body weight. Musculoskeletal symptoms were
reported by 77.1% of the students. Symptoms were
most prevalent in the neck, shoulders, upper back and
lower back5.
A magnetic resonance imaging study demonstrated
that increasing backpack loads significantly
compressed lumbar disc heights measured in the
midline sagittal plane (P < 0.05)6. This is the first
study to use advanced imaging to demonstrate how
backpack loads are responsible for a significant
amount of back pain in children, which in part, may
be due to changes in lumbar disc height or curvature6.
A team of researchers at Auburn University,
Australia studied 421 students and found that
backpacks carried with one-strap promoted lateral
spinal bending and shoulder elevation7. Additionally,
they noted that carrying a backpack promoted
significant forward lean of head and trunk7.
A study carried out on healthy male school-children
(n=200), mean (SD) age 12.5 (0.5) years, from high
schools in Mangalore, India showed that carrying a
backpack weighing 15% of body weight changes all
the postural angles (cranio-vertebral, head on neck,
head and neck on trunk, trunk and lower limb) in
preadolescent children8. A study was done in Canada
to evaluate the changes in children's trunk forward
lean (TFL), cranio-vertebral angle (CVA) and spinal
lordosis angle (LA) that occurred with high, medium
and low load locations during standing and walking.
Results indicated that significant changes occurred in
TFL and CVA when the backpack was loaded to 15%
body weight9.
Carrying a backpack over 2 shoulders is the most
efficient means of carriage, but often backpacks are
carried over 1 shoulder. Thirty-two children (12-13
years) were assessed under 2 load conditions using
the GAITRite system. No significant differences
were found in base of support, stride length, or
velocity when compared with the unloaded baseline
walk during backpack use with loads limited to 15%
of body weight10.
There is debate about a 10% versus 15% of body
weight cutoff point for safe weight of school
backpacks. A study was done in Pennsylvania, USA
using electromyography, posture evaluation, heart
rate, and ratings of perceived exertion and
perceptions of pain to find an acceptable backpack
load limit for middle school students11. Twenty
middle school students aged 11 to 14 (10 female and
10 male) volunteered for the study. The subjects
completed two tests, standing stationary and walking
on a treadmill, where they carried 5% incremental
loads from 0% body mass (BM) to 20% BM. The
study indicated that the Borg-CR10 ratings and trunk
flexion angle for the walking trial indicated a
possible load limit of 10% BM due to the nonsignificant difference between 0 and 10% BM and
the significant difference between 10 and 15% BM11.
In a study done in Northern California12 531 5th to
12th grade students and their backpacks were
weighed. Students were individually interviewed
about how often they experienced pain while carrying
a backpack, the site of their pain, and if the pain had
interfered with school activities or led to medical
care. Data support the use of a 10% of body weight
cutoff for safe use of backpacks for all grade levels.
Greater relative backpack weight was associated with
upper- and mid-back pain reports but not neck or
lower back pain; it was also associated with lost
school time, lost school sports time, and greater
chiropractic utilization12.
There are certain things that parents should look for
when buying a backpack for their child13:
1.
Look for backpacks with wide, padded shoulder
straps. Narrow straps dig painfully into shoulders
and can hinder circulation, causing numbness or
tingling in the arms, which over time may cause
weakness in the hands. Padded shoulder straps
help absorb the load.
2.
Look for backpacks with "S" shaped shoulder
straps, which will ergonomically contour to the
child's body.
3.
Consider the weight of the backpack when
empty. For example, a canvas backpack will be
lighter than a leather one.
4.
Look for backpacks with a waist or chest strap.
This will help to keep the load close to the body
and help maintain proper balance.
5.
Look for backpacks with a built in back support.
6.
Look for backpacks with a lumbar pillow.
7.
Make sure the backpack is not too heavy. Even
when worn properly with both straps, leaning
forward to compensate for this extra weight can
affect the natural curve in the lumbar, or lower
back region. Extra weight may cause a rounding
of the shoulders and an increased curve in the
thoracic or upper back region. As a result, the
student may experience back, shoulder and neck
pain. A good rule to follow is to carry no more
than 10% of one's body weight.
8.
Consider purchasing a backpack with wheels.
Recommendations for backpack use include the
following13:
1.
Wear both shoulder straps. Slinging a backpack
over one shoulder causes a person to lean to one
side to compensate for the uneven weight,
curving the spine. Over time, this can cause
lower and upper back pain, strained shoulders
and neck, and even functional scoliosis, or
curvature of the spine. Teenage girls are
especially susceptible to scoliosis.
2.
Distribute weight evenly across your back. The
more spread out a load is, the less strain it puts
on any one part of your body. Load pack so the
heaviest items are right next to your back.
3.
Snug shoulder straps so the pack fits close to the
upper part of your back. The further a backpack's
load is from your back, the more it pulls you
backward and strains muscles between your
shoulders.
4.
Use the waist belt, and side/chest straps. Keep
the load close to your body. Keeping the pack
close to your hips also shifts "work" to your legs.
5.
The bottom should rest in the curve of your
lower back and the top touch just below the
vertebral prominence on your neck.
6.
Neatly pack your backpack, and try to keep items
in place.
References
1.
2.
3.
Viry P, Creveuil C, Marcelli C. Nonspecific back
pain in children: a search for associated factors
in 14-year-old schoolchildren. Revue Du
Rhumatisme 1999; 66:381–8.
Grimmer KA, Williams MT, Gill TK. The
association between adolescent head-on-neck
posture, backpack weight and anthropometric
features. Spine 1999; 24:2262–7.
Siambanes D, Martinez JW, Butler EW, Haider
T. Influence of school backpacks on adolescent
back pain. J Pediatr Orthop 2004; 24 (2): 211–
7.
4.
Negrini S, Carabalona R. Backpacks and
schoolchildren’s perception of load, associations
with back pain and factors determining the load.
Spine 2002; 27:187–95.
5.
Schoolbag
weight
and
musculoskeletal
symptoms in New Zealand secondary schools
Applied Ergonomics 2005; 36 (2): 193–8.
6.
Neuschwander TB, Cutrone J, Macias BR,
Cutrone S, Murthy G, Chambers H, Hargens AR.
The effect of backpacks on lumbar spine in
children: a standing magnetic resonance imaging
study. Spine 2010; 35(1):83-8.
7.
Pascoe DD, Pascoe DE, Wang YT, Shim DM,
Kim CK. Influence of carrying book bags on gait
cycle and posture of youths. Ergonomics 1997;
40 (6): 631–41.
8.
Ramprasad M, Alias J, Raghuveer AK. Effect of
backpack weight on postural angles in
preadolescent children Indian Pediatr 2009 Oct
14. Available from:
http://indianpediatrics.net/RP14.10.09/RP06.pdf.
9.
Brackley HM, Stevenson JM, Selinger JC. Effect
of backpack load placement on posture and
spinal curvature in prepubescent children Work
2009; 32(3):351-60.
10. Connolly BH, Cook B, Hunter S, Laughter M,
Mills A, Nordtvedt N, Bush A. Effects of
backpack carriage on gait parameters in children.
Pediatr Phys Ther 2008; 20(4):347-55.
11. Bauer DH, Freivalds A. Backpack load limit
recommendation for middle school students
based on physiological and psychophysical
measurements. Work 2009; 32(3):339-50.
12. Moore MJ, White GL, Moore DL Association of
relative backpack weight with reported pain, pain
sites, medical utilization, and lost school time in
children and adolescents J Sch Health 2007;
77(5): 232–9.
13. Pistolese RA. Book bags: What every parent
should know. Available from:
http://www.chiro.org/LINKS/FULL/Book_Bags.
shtml
G N Lucas
Joint Editor